Air filters are generally known in the art and are employed in a variety of applications including heating and ventilation systems. A typical air filter is composed of a filtering material; often paper, a nonwoven material or foam, and a frame or housing that supports the filtering material. Conventional air filters are typically designed to remove particulate matter from the air.
In some applications, particularly those related to commercial and industrial operations, the ventilation ducts may be quite large. Typically, several air filters are used in a filter bank. These filters may be installed into individual cells of an array or frame for holding individual filters or may slide into a rack that is adapted to hold a row of air filters in a side-by-side arrangement. Thus, an array of air filters arranged adjacent to one another is typically employed as a filter bank.
In an arrangement of air filters where the air filters are installed by sliding the air filters into a rack that is adapted to hold a row of filters in a filter bank, the air filters are often difficult to remove when it becomes necessary to change the air filters. This difficulty may be further increased in larger air handling systems having multiple large rows of filters in a filter bank. This is because a conventional side-by-side arrangement of air filters in a filter bank requires retrieval on a one-by-one basis. The air filters located farthest from the access point are frequently retrieved with a hook, wire or specialized devices constructed by maintenance personnel. This process is often very difficult and very time consuming. In addition, the handling and disposal of individual filters with caked with dust presents further problems both inside the air handling equipment and in the utility rooms where the air handling equipment is located. The difficulty in removing the air filters may result in the dust and debris caked onto the filter being accidentally dislodged from the air filter and into the air ducts or air handling equipment.
Moreover, the conventional side-by-side arrangement of air filters in a filter bank often results in a small gap or space between adjacent filters. As a result, a portion of air flow may avoid being filtered by the filter bank, bypassing the air filters (known as air bypass), and prior to being circulated throughout the building. This may result in detrimental effects of unfiltered air flowing through a ventilation system, including adverse effects on individuals. In addition to these effects on individuals, unfiltered air flow may also induce mechanical problems within the ventilation system itself, which may result in improper heating and cooling operations within a building structure. Dust particles may be deposited on the heating and cooling coils, clogging the coils and impeding proper operation of the ventilation system. Cleaning such coils is both time consuming and expensive.
One solution to the problem of air bypass is described in U.S. Pat. No. 6,916,352 to Sutton et al. and relates to the use of “I” shaped connectors to join adjacent filters in a filter bank. The connectors are used to join individual filters in side-by-side relationship as they are inserted into a track or opening in a filter bank. Sides of adjoining filter panels are inserted into the opposed channels of the “I”-shaped connectors. The “I”-shaped connector fills the gap between the sides of the adjacent filters to reduce air bypass between the sides of adjacent filters. The disadvantage with this design is the need for separate, non-integral connector pieces that must be joined to each filter upon installation.
Because the connector piece is inserted separately from the air filter, such an air filter installation process would disadvantageously be more time-consuming and cumbersome than that of installing filters alone. There is also the risk that an installer may inadvertently drop a connector piece into the filter bank and be forced to extract and reposition it, prolonging the installation process. In addition, installation may be dependent upon having an adequate supply of both connector pieces and air filters on site, possibly requiring installers to transport an increased volume of materials and supplies to installation sites.
While these connectors are described as reducing air bypass, the connectors are not described as securely attaching adjacent air filter together for efficient removal of the filters. Moreover, unless the individual connector pieces are disposable, they each must be removed from each filter upon extraction of the filters from the filter bank. This separation operation can be time consuming and can generate handling and disposal problems both within the air handling equipment and in the utility rooms where the air handling equipment is located.
Therefore, it is readily apparent that there is a need for an air filter that addresses these problems.